Functional Connectivity & Stimulation-enhanced Therapy Post Stroke

After stroke, it is common for individuals to experience hand impairment. This deficit can severely restrict functional ability and independence. Recovery of hand function following stroke is highly variable. In this study, the investigators will use brain imaging to predict individual response to treatment. Survivors of stroke will receive upper extremity therapy while they concurrently receive imperceptible vibration to the wrist aimed to enhance therapy outcomes.

The ability to predict individuals' responses to treatment can enable effective allocation of a treatment to likely responders. The long-term goal is to determine whether acute changes in brain functional connectivity immediately after one treatment session can predict ultimate gains in motor function after completing multiple treatment sessions. The objective of this study is to determine feasibility and to examine association between change in brain functional connectivity after one session and motor gains after completion of all treatment sessions. This study is a prospective single-cohort longitudinal study. The treatment is task-practice therapy (3d/wk, 18-session) accompanied with concurrent imperceptible wrist vibration that is intended to prime the cortical sensorimotor network and enhance hand functional recovery in chronic stroke survivors. Hand function will be assessed before/after therapy and at 1-month follow-up. Connectivity will be assessed using fMRI and EEG before and after a treatment session.

Imperceptible vibration applied to the wrist during a standardized hand task practice therapy program.

Change in hand motor function as measured by the Box and Block Test. The test measures the number of blocks that a participant moves within one minute. The scale ranges from 0 to a positive number. Higher numbers represent better outcomes.

Change in hand motor function as measured by the Box and Block Test. The test measures the number of blocks that a participant moves within one minute. The scale ranges from 0 to a positive number. Higher numbers represent better outcomes.

Change in hand motor function as measured by the Wolf Motor Function Test Time. This test measures time to complete upper extremity movements in seconds. More negative values represent a greater reduction in time, thus better outcomes.

Change in hand motor function as measured by the Wolf Motor Function Test Time. This test measures time to complete upper extremity movements in seconds. More negative values represent a greater reduction in time, thus better outcomes.

Inclusion Criteria: Age = 18 or older At least 6 months post-stroke Moderate upper limb impairment with the ability to participate in hand task practices Fingertip touch sensory deficits (e.g., Monofilament>2.83, 2-point discrimination>5mm, sense of numbness, tingling) Exclusion Criteria: Complete upper limb deafferentation Rigidity (Modified Ashworth Scale=5) Botulinum toxin injection within 3 months prior to enrollment or during enrollment Brainstem stroke Comorbidity (peripheral neuropathy, orthopaedic conditions in the hand that limit ranges of motion, premorbid neurologic conditions, compromised skin integrity of the hand/wrist due to long-term use of blood thinners) Concurrent upper extremity rehabilitation therapy Language barrier or cognitive impairment that precludes following instructions or providing consent MRI incompatible.